The substrate processing apparatus is an apparatus for manufacturing semiconductor devices by performing a specified process such as CVD, dry etching, or sputtering on a substrate such as a silicon wafer.
Substrate processing apparatus are grouped into single-wafer type substrate processing apparatus for processing one substrate at a time; and batch-type substrate processing apparatus for processing a specified number of substrates at one time.
In methods for manufacturing semiconductor integrated circuit devices (hereinafter, called “IC”), vertical diffusion CVD apparatus are used in processes for forming a film and diffusing on the wafer.
Conventional vertical diffusion CVD apparatus of this type include a boat movement mechanism for moving a boat holding multiple wafers. This boat movement mechanism is structured to move the boat between a wafer transfer position, and a boat loading and unloading furnace position, and a wafer cooling position. This boat movement mechanism is disclosed for example in the patent document 1.
Namely, the boat movement mechanism for this type of vertical diffusion CVD apparatus contains two boat support arms each capable of swiveling and moving up and down. The boat movement mechanism is structured to support the boat by the boat support arms and to move the boat between the mount stand at the wafer transfer position, the boat loading and unloading furnace position, and the mount stand at the wafer cooling position.
The patent document 2 for example discloses a boat locking mechanism for locking the boat on the mount stands at the wafer transfer position and at the wafer cooling position, and the boat elevator for raising and lowering the boat and loading and unloading the boat into and from the reaction furnace.
However, this boat locking mechanism cannot lock the boat while the boat is moving between the wafer transfer position and boat loading and unloading furnace position and wafer cooling position, and therefore cannot prevent the boat from tipping over.
The patent document 3 on the other hand, discloses a boat locking mechanism containing an anti-tipping damper on the boat support arm to prevent the boat from tipping over during movement.
Patent document 1: Japanese Patent Non-Examined Publication No. 2001-338888
Patent document 2: Japanese Patent Non-Examined Publication No. 2003-258063
Patent document 3: Japanese Patent Non-Examined Publication No. 2004-71618